how do you measure mass in zero gravity?

[Nuke]

say you are a scientist doing an experiment aboard the iss and you need to know the mass of an object (for science!). what are the practical methods they would use to do that? i know astronomers have ways of determining the mass of distant celestial bodies but how is it done for smaller objects in the floaty lab?

Edited August 15, 2019 by Nuke

[ChainiaC]

Apply a measured amount of force and then measure the object's acceleration?

[Superfluous J]

You could attach it to a known mass with a string and get them spinning, and the center of mass of the group (the part of the string right in the center) will tell you their ratio. You'd have to account for the distance from each piece's edge to its center of mass, which you can determine by spinning the object by itself I guess.

There are probably better ways but hey it's not that much different than using a scale with sliding weights here on Earth.

[magnemoe]

50 minutes ago, ChainiaC said:

Apply a measured amount of force and then measure the object's acceleration?

This, with an small solid object you can vibrate it, with something like an spaceship measuring acceleration is easiest. 

Mass of say an asteroid is harder unless it has an moon. 

[kerbiloid]

(English wiki doesn't have this article, so in Russian)

https://ru.wikipedia.org/wiki/Измеритель_массы_тела_в_невесомости

 

[Nuke]

7 hours ago, kerbiloid said:

(English wiki doesn't have this article, so in Russian)

https://ru.wikipedia.org/wiki/Измеритель_массы_тела_в_невесомости

 

exactly what i was looking for and russian translates pretty well on google.